<template>
  <el-breadcrumb class="app-breadcrumb" separator="/">
    <transition-group name="breadcrumb">
      <el-breadcrumb-item v-for="(item,index) in levelList" :key="item.path">
        <span v-if="item.redirect==='noRedirect'||index==levelList.length-1" class="no-redirect">{{ item.meta.title }}</span>
        <a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
      </el-breadcrumb-item>
    </transition-group>
  </el-breadcrumb>
</template>

<script>
import pathToRegexp from 'path-to-regexp'
import { ref,watch } from 'vue'
import { useRoute } from 'vue-router'
export default {
  setup(){
    const isDashboard = function(route) {
      const name = route && route.name
      if (!name) {
        return false
      }
      return name.trim().toLocaleLowerCase() === 'Dashboard'.toLocaleLowerCase()
    }
    const route = useRoute();
    const levelList = ref(null);
    const getBreadcrumb = function(){
      let matched = route.matched.filter(item => item.meta && item.meta.title)
      const first = matched[0]
      if (!isDashboard(first)) {
        matched = [{ path: '/dashboard', meta: { title: 'Dashboard' }}].concat(matched)
      }
      levelList.value = matched.filter(item => item.meta && item.meta.title && item.meta.breadcrumb !== false)
    }
    
    const pathCompile = function(path) {
      const { params } = route
      let toPath = pathToRegexp.compile(path)
      return toPath(params)
    }
    const handleLink = function(item) {
      const { redirect, path } = item
      if (redirect) {
        router.push(redirect)
        return
      }
      router.push(pathCompile(path))
    }


    getBreadcrumb();
    watch(route,getBreadcrumb);
    return {
       handleLink,
       levelList
    }
  }
}
</script>

<style lang="scss" scoped>
.app-breadcrumb.el-breadcrumb {
  display: inline-block;
  font-size: 14px;
  line-height: 50px;
  margin-left: 8px;

  .no-redirect {
    color: #97a8be;
    cursor: text;
  }
}
</style>
